One of the most important parts of designing any product is to adhere to the norm of delightful harmony. One of the design norms outlined by Herman Dooyeweerd, it instructs designers to produce products that are delightful to use. Using something should not be a frustrating experience, and for a machine like Text2Type that we hope is used very often, this is ever the more true.

A problem we were running into was how to power all the parts we have, all needing different voltages, needs for stability, and sensitivity. The solenoids work at 12 volts 3 amps each, while the steppers and Pi work at 5 volts. While having the same voltage requirements, the steppers and Pi cannot be connected to the same source (without some isolation) as the motors will produce significant hash that would disrupt the Pi.

What could be classified as the most naive approach would be to have three isolated power systems, with three dangling power cords coming out of the printer. But this is not delightful. It would moreover be ridiculous to expect a user to plug in three separate cords to power one unit. It should also be noted that this problem is in no way Herculean or even difficult– it has been experienced and solved a thousand times over by millions of engineers.

Beyond saving the users a headache, the wire organization and centralization the PSU offers is saving us designers a headache. It has become easy to see how everything connects and verify that those connections are correct. And it is simply nicer to view, boosting morale and resolve to do good work. So even in such a trivial problem, the design norms are still important and cannot be ignored without making the product and project significantly worse.

In the words of Roman politician Sallust “Harmony makes small things grow. Lack of it makes big things decay.”